'Sleep well Hillary', says Republican presidential nominee Donald Trump ahead of debate

Republican presidential nominee Donald Trump has teased his Democratic rival Hillary Clinton to "sleep well" ahead of the first presidential debate next week which is likely to attract a record number of viewership.

Clinton appeared at no public events on Tuesday with less than two months before the election, and 70-year-old Trump promptly ridiculed her "taking the day off". "Hillary Clinton is taking the day off again, she needs the rest. Sleep well Hillary - see you at the debate!" Trump said in a tweet after it was reported that Clinton has taken a day's off from her grilling campaign schedule.

Hillary Clinton is taking the day off again, she needs the rest. Sleep well Hillary - see you at the debate!

— Donald J. Trump (@realDonaldTrump) September 20, 2016

It was only the latest dig on 68-year-old Clinton by Trump, who has repeatedly mocked his rival's 'stamina,' although he wished her well after she was diagnosed with pneumonia after she left the 9/11 commemoration ceremony. The first of the series of three presidential debates are scheduled for September 26 in New York.

In American presidential election a lot depends on performance of a candidate in these three debates. Given the sharp polarization of voters during the general elections, the first presidential debate is expected to attract a record 100 million viewership, The Hill newspaper said.

"A debate with an audience that size would be something never seen before in US politics and would be a figure close to what the Super Bowl gets," the newspaper said. The other two presidential debates have been scheduled for October 9 and October 19. Their running mates Tim Kaine and Mike Pence would have the sole vice presidential debates on October 4.